1. Technical Field
The disclosure generally relates to light emitting diode (LED) lamps, and particularly to an LED lamp with an adjustable lamp cap for facilitating assembly of the LED lamp to a lamp holder and facilitating adjustment of an illumination orientation of the LED lamp.
2. Description of Related Art
In recent years, LED lamps are preferred for use rather than CCFLs (cold cathode fluorescent lamps) and other light sources due to their excellent properties, including high brightness, energy saving, long lifespan, wide color range, and etc. Generally, a CCFL is elongated in profile and has a pair of electrically conductive poles provided at each of two ends of the CCFL. The conductive poles are inserted into a lamp holder, whereby the CCFL can get power through the lamp holder. Since the CCFL diffuses light outwardly from an outer surface thereof uniformly, the CCFL can be freely and easily mounted to the lamp holder without the need to adjust an illumination orientation of the CCFL. However, a light emitting surface of an LED is usually hemispherical and a beam angle of the LED is usually not larger than 120 degrees, which means the LED just can illuminate about two-thirds of a space in front of the LED emitting surface. Thus, an illumination orientation of the light emitting surface of the LED is very important to an LED lamp and should be accurately controlled. When the CCFL is substituted by the LED lamp and the LED lamp is mounted to the lamp holder which is originally used to mount the CCFL, an illumination orientation of the light emitting surface of the LED should be easily regulated to maintain the LED lamp to have a proper illumination orientation without bringing inconveniency for assembly the LED lamp to the lamp holder so that the LED lamp can be accurately and easily mounted to the lamp holder.
For the foregoing reasons, therefore, there is a need in the art for an LED lamp which overcomes the limitations described above.